High frequency continuous wave ignition system

ABSTRACT

An ignition system employing continuous-wave high-frequency spark energy, makes use of a special ignition-switch circuit. The special circuit switches only control winding current of an oscillator that supplies the spark energy. Consequently, high current oscillator energy may be directly and permanently connected.

United States Patent 1 1 1111 3,779,226 Canup Dec. 18, 1973 [5 HIGH FREQUENCY CONTINUOUS WAVE 3,020,904 2/1962 Kerr 123/148 E IGNITION SYSTEM 3,299,875 1/1967 Skay 123/148 E [75] Inventor: Robert E. Canup, Richmond, Va.

Primary bxammer-Laurence M. Goodridge [73] Assignee: Texaco Inc., New York, NY. Am)r Thom H, Whale er [22] Filed: Mar. 6, 1972 21 Appl. No.: 232,094 [571 ABSTRACT An ignition system employing continuous-wave high- [52] US. Cl. 123/148 E, 315/209 frequency spark gy makes e f a special igni- [51] Int. Cl. F02p 3/02 tionswitch circuit The special Circuit Switches only [58] Field of Search 123/148 E; 315/209 Comm Winding Current of an Oscillator that Supplies the spark energy. Consequently, high current oscilla- 5 References Cited tor energy may be directly and permanently con- UNITED STATES PATENTS 3,407,795 10/1968 Aiken et a1 123/148 E 7 Claims, 1 Drawing Figure A? fflfi/SZ''x/fi lfr/V/T/ON n; sw/m/ HIGH FREQUENCY CONTINUOUS WAVE IGNITION SYSTEM CROSS REFERENCE TO RELATED APPLICATIONS Subject matter of this application is related to that of my copending applications :Ser. No. 100,642, filed Dec. 22, 1970 DNo.71,898);Ser. No. 193,909, filed Oct. 29, 1971 (DNo.72,528); and Ser. No. 209,060, filed Dec. 17, 1971 (DNO.72,547).

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention concerns ignition systems for internal combustion engines, generally. More specifically, it relates to an improvement that is of concern particularly in relation to high-frequency continuous-wave ignition systems.

2. Description of the Prior Art While prior arrangements for making use of highfrequency continuous-wave signals in ignition systems have been proposed, such prior arrangements have not been particularly successful for various reasons. In the course of overcoming the prior difficulties, it has been discovered that a relatively high current flow is involved in the power supply to the oscillator, and this has resulted in a problem with the usual arrangement for switching the ignition power supply through the usual automotive ignition switch.

Consequently, it is an object of this invention to provide an improved ignition system of the high-frequency continuous-wave type which will permit use of a permanently connected power supply to the oscillator.

SUMMARY OF THE INVENTION Briefly, this invention deals with a high-frequency continuous-wave ignition system foran internal combustion engine. Said system includes an oscillator for supplying continuous-wave controlled-duration spark energy, and the said oscillator has a control winding for starting and stopping the oscillator at the beginning and end of each spark interval. The system also includes means controlled by said engine for cutting off and supplying a DC bias current to said control winding, and an ignition switch for controlling energization of said ignition system including said DC bias current circuit. In relation to the foregoing, the invention concerns the improvement that comprises circuit means for energizing said oscillator without passing through said ignition switch.

Again, briefly, the invention relates to a highfrequency continuous-wave ignition system for an internal combustion engine where said system includes an oscillator for supplying continuous-wave controlledduration spark energy. The said oscillator has a control winding for starting and stopping the oscillator at the beginning and end of each spark interval, and it has means for control by said engine for cutting off and applying DC bias current to said control winding. The oscillator also has an ignition switch having a pair of ganged poles and a pair of off-position contacts for controlling energization of said ignition system, including said DC bias current circuit. In relation to the foregoing, the invention concerns the improvement that comprises a permanent direct connection for energizing said oscillator, and first cirucit connections from the end of said control winding to said ganged poles, as

well as second circuit connections from said offposition contacts to ground.

Once more, briefly, the invention concerns a highfrequency continuous-wave ignition system for an internal combustion engine which comprises, in combination, an oscillator for supplying continuous-wave controlled-duration spark energy. The said oscillator has a control winding for starting and stopping the oscillator at the beginning and end of each spark interval. It also comprises means controlled by said engine for cutting off and supplying a DC bias current to said control winding, and an ignition switch that, in turn, comprises a pair of ganged poles and a pair of off-position contacts. The combination also comprises means for grounding said control winding when said ignition switch is off, which includes circuit connections from said contacts to ground.

BRIEF DESCRIPTION OF THE DRAWING The foregoing and other objects and benefits of the invention will be more fully set forth below in connection with the best mode contemplated by the inventor of carrying out the invention, and in connection with which there are illustrations provided in the drawing, wherein:

The drawing FIGURE is a schematic circuit diagram illustrating a system according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the course of developing ignition systems that employ high-frequency continuous-wave energy for the spark, it has been found that the oscillator (DC-to-AC converter using solid-state electronic elements) tends to draw rather substantial amounts of current. Consequently, for such systems to be successful, there is necessitated relatively heavy-gauge wiring in the powersupply circuit to the oscillator. Since it is standard practice to provide an ignition switch that is located a substantial distance away from the engine, for controlling energization of the ignition system, there would be required a substantial length of heavy-gauge wiring in addition to the use of heavy-duty switch structure in the ignition switch itself for successful use of the subject type ignition system. However, by making use of this invention, ignition-switch control is provided in such manner that the power-supply connection to the oscillator may be permanent and, consequently, it can physically bypass the long distance required to go from the battery to the ignition-switch location and back to the engine where the ignition oscillator is located.

Thus, referring to the figure of drawing, it is to be noted that there is illustrated an ignition system that employs a single transformer 11. This system is in accordance with the type of high-frequency continuouswave ignition systems that are illustrated and described in my earlier copending applications Ser. No. 193,909, filed Oct. 29, 1971, and Ser. No. 209,060, filed Dec. 17, 1971, both referred to above, as well as the first application Ser. No. 100,642, filed Dec. 22, 1970.

Since the details of this type of ignition system have been described in those earlier filed applications, it is sufficient to note for the purpose of this disclosure that the system illustrated in this application includes the single transfonner 11 which has a secondary or output winding 12. Winding I2 is connected to ground at one end, as illustrated. The other end of the winding 12 is connected to the distributor cap of an internal combustion engine via a connector 13. This is indicated by the caption TO DIST. CAP. Input of high-frequency continuous-wave energy is supplied to the transformer 11 by an oxcillator 16. Oscillator 16 includes a centertapped primary winding 17 for supplying the input energy to induce the high-voltage output in winding 12. Details of the operation of oscillator 16 are not necessary to an understanding of this invention, and therefore reference may be had to the foregoing three copending applications for such details.

It is pointed out that the oscillator and ignition system of this invention, as well as those of the three earlier inventions noted above, include on the transformer a control winding 20. This winding 20 has a DC bias current supplied therethrough in such manner as to insure the instant starting of the oscillator 16 when such current is interrupted.

In the illustrated system, there is a so-called starting network 21 that is shown enclosed in dashed lines. This is only applicable to the case where the spark intervals are controlled by breaker points, although the invention may be applied also to ignition systems employing other engine-controlled switching in the circuit of the control winding 20.

The details of the operation of the network 21 are fully explained in my aforementioned copending application Ser. No. 100,642, filed Dec. 22, 1970. Briefly, the purpose is to absorb the reactive voltage that would cause arcing at the breaker points, without causing sufficient loading of the oscillator magnetic circuit to prevent oscillation.

As has been noted, this invention is just as applicable to an ignition system that employs nonbreaker-point engine-controlled switching in the control winding circuit. For example, see either of my earlier applications Ser. No. 193,909, filed Oct. 29, 1971, or Ser. No. 209,060, filed 12/17/1971, (DNo.72,547). In such cases the starting network 21 would be eliminated and a breakerless engine-controlled arrangement (not shown) would replace the breaker points 23.

It will be observed that there is a permanent direct connection that leads from the center tap on winding 17 through a resistor 31 and a fuse 32 to one side of a battery 33, the other side of which battery is connected to ground. This permanent connection is made of adequately heavy-gauge wire'so that the oscillator will operate properly and maintain full voltage applied to the oscillator 16, at all times.

In order to provide the usual ignition-switch control of the system, there is a three-pole ganged switch 36 that has four different position-switch contacts cooperating with each pole. The numbers for these positions are arbitrarily assigned, going from left to right in the drawing illustration. The second position is that illustrated in the drawing with the ganged switch arms in contact therewith. Also, as is common with automobile ignition-switch arrangements, the third and fourth positions are for each of the running and starting operations, respectively. In the illustrated circuit, there is a contact 39 that has a circuit connection 40 leading therefrom, which goes to the starting solenoid (not shown), as is indicated by the caption. Also in the usual manner, there is a spring bias (not shown) on the fourth position so that as soon as the engine starts, the switch is released, and it returns automatically to the third position.

A contact 43 on the uppermostbank is connected to the high-voltage side of the battery 33 via a circuit connector 44. Consequently, when the ignition switch is in the third, or run" position, the battery 33 is connected via a connector 45, and the connector 44 to the contact 43. From there, a circuit will be continued over an arm 48 of the ignition switch to a circuit connector 49. The connector 49 leads to one end of the control winding 20 via a resistor 50. The other end of the winding 20 is connected to the circuit, as indicated above, that leads to the breaker points 23 or to the alternative (not shown) enginecontrolled circuit element that determines when this DC bias circuit from the battery 33 will be broken.

Also, as already indicated, the same enginecontrolled switching element (or breaker points 23) will determine the termination of the oscillation when the switching element is closed again. Thus, so long as the ignition switch 36 is in its third (operate) position, the system acts in the same manner as has been described in my earlier applications, with the sparkduration oscillating periods under control of the engine-operating elements in a usual manner, except that the oscillator 16 is not getting its power supply through the ignition switch 36.

However, when the engine is turned off, e.g., by switching the ignition switch to the position illustrated, even though the power supply to the oscillator 16 is not terminated, the oscillations will be stopped and the oscillator 16 maintained inoperative. The foregoing is by reason of an added circuit that is connected to control winding 20. This added circuit includes, in addition to the circuit connector 49 and switch arm 48, a circuit connector 52. Connector 52 joins an of contact 53 of the ignition switch 36 with an auxiliary contact 54. Also connected to contact 54, there is a circuit connector 55 that leads to another switch arm 56 of the ignition switch 36.

When the switch arm 56 is in either the auxiliary or off (second) positions, it contacts one or the other of switch contacts 60 or 61. Both of these contacts 60 and 61 have a circuit connector 62 joined therewith. Consequently, a circuit connection is completed to the other end of the control winding 20 in either of the first or second ignition-switch positions.

The foregoing circuit, i.e., through ignition switch 36, applies a direct short-circuit across control winding 20 whenever the switch is in its off or auxiliary positions. Also, both ends of the winding 20 are grounded by having a connector 65 that is connected into the connector 55 so that the switch arm 56 is always grounded while there is, in addition, a diode 66 connected between the upper end (as illustrated) of the winding 20 and ground. These connections insure the cut-off and maintenance of the oscillator 16 in its nonoscillating state.

In the foregoing manner, the circuit that includes the contacts of ignition switch 36 may employ relatively light-gauge wiring since the DC bias current as well as the short-circuiting currents for control winding 20 are both low-current conditions on the order of a few milliamperes. On the other hand, the current required for the oscillator averages in the neighborhood of ten amperes with peak currents as-high as fifty amperes..

While the invention has been described above in considerable detail in accordance with the applicable statutes, this is not to be taken as limiting the invention in any way, but merely as being descriptive thereof.

What l claim is:

I. In a high-frequency continuous-wave ignition system for an internal combustion engine, said system including an oscillator for supplying continuous-wave controlled-duration spark energy, said oscillator having a power supply and a control winding for starting and stopping the oscillator at the beginning and end of each spark interval, means controlled by said engine for cutting off and supplying a DC bias current to said control winding, and an ignition switch for controlling energization of said ignition system including said DC bias current circuit, the improvement comprising circuit means including a permanent direct connection for energizing said oscillator without passing through said ignition switch.

2. The invention according to claim 1, further comprising means for grounding both sides of said control winding when said ignition switch is off.

3. The invention according to claim 2, wherein said ignition switch comprises a pair of ganged poles, and

a pair of off position contacts,

and wherein said grounding means comprises circuit connections from said contacts to ground.

4. in a high-frequency continuous-wave ignition system for an internal combustion engine, said system including an oscillator for supplying continuous-wave controlled-duration spark energy, said oscillator having a power supply and a control winding for starting and stopping the oscillator at the beginning and end of each spark interval, means controlled by said engine for cutting off and supplying a DC bias current to said control winding, and an ignition switch having a pair of ganged poles plus a pair of off-position contacts for controlling energization of said ignition system including said DC bias current circuit, the improvement comprising a permanent direct connection for energizing said oscillator without passing through said ignition switch, first circuit connections from the ends of said control winding to said ganged poles, and second circuit connections from said off-position contacts to ground. 5. A high-frequency continuous-wave ignition for an internal combustion engine, comprising in combination an oscillator having a power supply and a control winding for starting and stopping the oscillator at the beginning and end of each spark interval, means controlled by said engine for cutting off and applying a DC bias current to said control winding, an ignition switch for controlling energization of said ignition system including a DC bias current circuit but excluding said power supply, and circuit means including a permanent direct connection for energizing said oscillator without passing through said ignition switch. 6. A combination according to claim 5, further comprising means for grounding both sides of said control winding when said ignition switch is off. 7. A combination according to claim 6, wherein said ignition switch comprises a pair of ganged poles, and a pair of off position contacts, and wherein said grounding means comprises circuit connections from said contacts to ground. 

1. In a high-frequency continuous-wave ignition system for an internal combustion engine, said system including an oscillator for supplying continuous-wave controlled-duration spark energy, said oscillator having a power supply and a control winding for starting and stopping the oscillator at the beginning and end of each spark interval, means controlled by said engine for cutting off and supplying a DC bias current to said control winding, and an ignition switch for controlling energization of said ignition system including said DC bias current circuit, the improvement comprising circuit means including a permanent direct connection for energizing said oscillator without passing through said ignition switch.
 2. The invention according to claim 1, further comprising means for grounding both sides of said control winding when said ignition switch is off.
 3. The invention according to claim 2, wherein said ignition switch comprises a pair of ganged poles, and a pair of off position contacts, and wherein said grounding means comprises circuit connections from said contacts to ground.
 4. In a high-frequency continuous-wave ignition system for an internal combustion engine, said system including an oscillator for supplying continuous-wave controlled-duration spark energy, said oscillator having a power supply and a control winding for starting and stopping the oscillator at the beginning and end of each spark interval, means controLled by said engine for cutting off and supplying a DC bias current to said control winding, and an ignition switch having a pair of ganged poles plus a pair of off-position contacts for controlling energization of said ignition system including said DC bias current circuit, the improvement comprising a permanent direct connection for energizing said oscillator without passing through said ignition switch, first circuit connections from the ends of said control winding to said ganged poles, and second circuit connections from said off-position contacts to ground.
 5. A high-frequency continuous-wave ignition for an internal combustion engine, comprising in combination an oscillator having a power supply and a control winding for starting and stopping the oscillator at the beginning and end of each spark interval, means controlled by said engine for cutting off and applying a DC bias current to said control winding, an ignition switch for controlling energization of said ignition system including a DC bias current circuit but excluding said power supply, and circuit means including a permanent direct connection for energizing said oscillator without passing through said ignition switch.
 6. A combination according to claim 5, further comprising means for grounding both sides of said control winding when said ignition switch is off.
 7. A combination according to claim 6, wherein said ignition switch comprises a pair of ganged poles, and a pair of off position contacts, and wherein said grounding means comprises circuit connections from said contacts to ground. 